Objective:To master the current status of iodine nutrition of residents in Tongchuan City and provide basis for policy adjustment of relevant department.Methods:In 2019, the cross-sectional survey method was used to divide 5 sampling areas in the 4 districts (counties) of Tongchuan City according to the east, west, south, north, and middle, and each area sampled 1 township (street, including at least 1 street), each township (street) selected one elementary school, each elementary school selected 42 non-boarding students aged 8 - 10, and each township (street) selected 21 pregnant women as the survey subjects. Home salt samples and urine samples were collected, salt iodine and urinary iodine were monitored, and thyroid examinations were performed on students.Results:A total of 1 260 salt samples were collected, including 2 non-iodized salt and 1 240 qualified iodized salt; the median salt iodine was 24.32 mg/kg; the coverage rate of iodized salt, the qualified rate of iodized salt, and the edible rate of qualified iodized salt were 99.84% (1 258/1 260), 98.57% (1 240/1 258) and 98.41% (1 240/1 260), respectively. A total of 840 urine samples were collected from students, the median urinary iodine was 196.19 μg/L. The medians urinary iodine of students aged 8, 9, and 10 were 182.59, 222.16, and 190.36 μg/L, respectively. The median urinary iodine of male and female students were 211.27 and 186.76 μg/L. A total of 840 students were tested for thyroid, thyroid rate was 1.79% (15/840) by B-ultrasound. A total of 420 urine samples were tested of pregnant women. The median urinary iodine was 155.05 μg/L. The medians urinary iodine of pregnant women in the first, second and third trimester of pregnancy were 166.79, 176.11 and 129.82 μg/L, respectively. There was a statistically significant difference in urine iodine content of pregnant women in different pregnancy periods ( H = 9.317, P < 0.05). Conclusions:The iodine nutrition level of residents in Tongchuan City is generally suitable. Pregnant women's urinary iodine shows iodine deficiency in the third trimester. Monitoring of iodine nutrition of pregnant women should be strengthened, classified guidance and scientific iodine supplementation should be adhered, to ensure the appropriate level of iodine nutrition for pregnant women.

Chemotherapy resistance plays a pivotal role in the prognosis and therapeutic failure of patients with colorectal cancer(CRC).Cisplatin(DDP)-resistant cells exhibit an inherent ability to evade the toxic chemotherapeutic drug effects which are characterized by the activation of slow-cycle programs and DNA repair.Among the elements that lead to DDP resistance,O6-methylguanine(O6-MG)-DNA-meth-yltransferase(MGMT),a DNA-repair enzyme,performs a quintessential role.In this study,we clarify the significant involvement of MGMT in conferring DDP resistance in CRC,elucidating the underlying mechanism of the regulatory actions of MGMT.A notable upregulation of MGMT in DDP-resistant cancer cells was found in our study,and MGMT repression amplifies the sensitivity of these cells to DDP treatment in vitro and in vivo.Conversely,in cancer cells,MGMT overexpression abolishes their sensi-tivity to DDP treatment.Mechanistically,the interaction between MGMT and cyclin dependent kinase 1(CDK1)inducing slow-cycling cells is attainted via the promotion of ubiquitination degradation of CDK1.Meanwhile,to achieve nonhomologous end joining,MGMT interacts with XRCC6 to resist chemotherapy drugs.Our transcriptome data from samples of 88 patients with CRC suggest that MGMT expression is co-related with the Wnt signaling pathway activation,and several Wnt inhibitors can repress drug-resistant cells.In summary,our results point out that MGMT is a potential therapeutic target and predictive marker of chemoresistance in CRC.

【Objective】 To explore the correlation of preoperative fibrinogen-to-albumin ratio （FAR） with the clinicopathological characteristics and prognosis of patients with rectal cancer so as to clarify the role of coagulation function and nutritional status in the occurrence and progression of tumors. 【Methods】 We retrospectively analyzed the clinicopathological data of 647 patients with rectal cancer who underwent radical resection in The First Affiliated Hospital of Xi’an Jiaotong University from January 1， 2013 to December 31， 2016. According to the optimal cut-off point value of FAR determined by receiver operating characteristic curve， 647 rectal cancer patients were divided into high FAR level group and low FAR level group. The correlation between different preoperative FAR levels and clinicopathological characteristics of rectal cancer patients was analyzed. Multivariate Cox regression analysis was used to analyze the independent risk factors for the prognosis of rectal cancer patients. R software was used to construct the nomogram， and C index and calibration chart were used to evaluate the prediction efficiency of the nomogram. 【Results】 Preoperative FAR levels had a good predictive value for the prognosis of rectal cancer patients. The area under ROC curve was 0.771， the optimal cut-off point was 0.092， and the Youden index was 0.446. There were statistically significant differences in age， T stage， N stage， TNM stage， preoperative CEA levels and preoperative CA19-9 levels between rectal cancer patients with different preoperative FAR levels （P<0.05）. The overrall survival and disease-free survival of rectal cancer patients with different preoperative FAR levels had statistically significant differences （P<0.05）. In the multivariate analysis， preoperative FAR levels （≥0.092， HR=3.298， 95% CI： 2.365―4.600， P<0.001）， age （≥60 years， HR=2.110， 95% CI： 1.479―3.012， P<0.001）， TNM stage （Ⅲ grade， HR=6.743， 95% CI： 2.771―16.771， P<0.001）， grade of differentiation （poor， HR=1.639， 95% CI： 1.104―2.432，P=0.014）， preoperative CA19-9 levels （≥37 U/mL， HR=2.205， 95% CI： 1.529―3.180， P<0.001） and not perform postoperative chemoradiotherapy（HR=1.792， 95% CI： 1.294―2.480，P<0.001） were independent risk factors of overall survival for patients with rectal cancer. OS and DFS nomograms of rectal cancer were established by the Rlanguage software， and the C-index was （0.781， 95% CI： 0.749―0.815； 0.754， 95% CI： 0.693―0.760）， respectively. The calibration curve of the nomogram showed high consistence between predictions and actual results for 1-year， 3-year， 5-year OS and DFS. 【Conclusion】 The preoperative high FAR level was an independent risk factor for the prognosis of patients with rectal cancer. It can be supplemented with pathological factors such as TNM stage as prognostic indicators for patients with rectal cancer， which may be helpful for clinicians to follow up or make beneficial treatment for rectal cancer patients.